1. Field of the Invention
The present disclosure generally relates to bonding technology, and more particularly, to systems and methods for bonding semiconductor-semiconductor, semiconductor-ceramic, semiconductor-metal, and/or metal-ceramic substrates using microwave energy. These combinations are used in semiconductor applications where some of these substrates could be carrying an electronic device.
2. Description of the Related Art
Various devices have separate parts that are bonded together to gain more utility. For example, in many applications, different substrates are bonded together by interlayers in order to achieve higher capabilities. In an alternative example, electronic components are bonded (“interconnected”) to electrical pathways to allow communication between the electrical components.
Conventional techniques for bonding substrates and forming interconnections, however, rely upon the use of elevated temperatures which may lead to problems, including premature failures and reliability concerns.
In one example, conventional substrate bonding can result in bulk heating of one or more of the substrates. Owing to differences in the coefficient of thermal expansion of the substrates, residual stresses may then arise during and/or after the bonding process. Furthermore, the bulk heating of the substrates during the bonding process may result in undesirable diffusion of dopant materials into the substrates. These residual stresses and dopants may result in premature failure of the bond.
In another example, conventional substrate bonding can also limit the maximum bond strength when a low-melting-temperature interlayer material is used.
Conventional techniques for forming electrical interconnections, or interconnects, are also problematic in the presence of low melting point materials such as packaging materials. The typical solders used for interconnects are often re-shaped at elevated temperature after initial deposition. Bulk heating of the region about the interconnects may result in undesirable degradation, migration, and/or loss of the packaging layer adjacent the interconnects.
From the foregoing, then, there is a need for improved systems and methods for bonding components such as substrates and electrical interconnects.